A Boeing 777 airplane lies burned on the runway after it crash landed at San Francisco International Airport July 6, 2013.(Photo: Ezra Shaw, Getty Images)

SAN FRANCISCO -- An Asiana Airlines flight from Seoul crashed on landing at San Francisco's airport Saturday, killing two passengers, injuring more than 180 and and forcing dozens of frightened passengers and crew to scamper from the heavily damaged aircraft before it was engulfed in smoke and flames.

There were 307 on board, including 16 crew. Officials said 123 escaped without injury and 181 were hospitalized or treated for injuries. Among the injured, 49 are in serious condition and five at San Francisco General Hospital, including a child, remain critical. Among the 47 others at San Francisco General, several were treated for minor injuries, including fractures and abrasions, and were released Saturday night.

"It was all over in 10 seconds," says Vedpa Singh, who suffered a fractured collarbone. "We heard a big bang, and it was over."

The cause of the crash has not been determined, but the FBI has has ruled out terrorism. The Boeing 777 appeared to have touched down tail-first and short of the runway. A sheered off tail section rested several hundred feet from the main body of the aircraft, and debris from the plane littered the runway. Passenger Janghyung Lee told USA Today that the aircraft rattled wildly before landing.

Images from the scene showed smoke billowing from the plane and emergency exits open from the plane's fuselage. Gaping holes could be seen along the top of the fuselage, blackened by fire.

The flight, which originated in Shanghai China before stopping in Seoul enroute to San Francisco, was carrying 61 U.S. citizens, 77 South Koreans and 141 Chinese. All passengers and crew were accounted for by Saturday night. It took several hours to account for everyone on the flight.

"We're lucky we have this many survivors,'' said San Francisco Mayor Ed Lee.

It was the first fatal crash of a commercial airline in the U.S. since February 2009, which was when Colgan Air Flight 3407 went down in Clarence.

National Transportation Safety Board Chairman Deborah Hersman declined comment on whether pilot error caused the crash. "We have not determined what the focus of this investigation is yet,'' she said before leaving Washington, D.C, with a crash site-bound team of investigators . "We will be looking at everything. Everything is on the table at this point.''

Hersman said the investigative team would look at all possible crash causes. "Obviously we have a lot of work to do,'' Hersman said before departing Washington for the crash scene.

The investigators will work with the FAA, the aircraft's manufacturer Boeing and Korea's Air and Accident Investigation Board, Hersman said. Analysts in Washington, D.C., will examine air-traffic control records, weather and aircraft maintenance issues, she said. Investigators on site will examine the aircraft, the cockpit data recorders and the scene.